View Compilation Error

0_0_21212824_1287.cpp: In function 'int main()':
0_0_21212824_1287.cpp:29:23: error: 'memset' was not declared in this scope
   memset(b,0,sizeof(b));
                       ^
0_0_21212824_1287.cpp: At global scope:
0_0_21212824_1287.cpp:50:1: error: expected unqualified-id before '--' token
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 ^